【摘要】 松辽盆地北部古龙断陷的地震地质条件复杂,三维地震资料品质较差,所以提高地震资料的信噪比和断陷期地层的成像精度是当前地震资料处理的研究重点.在提高地震资料信噪比方面,本文进行了十字交叉排列面波压制技术、压制规则干扰的减去法多次波压制技术和基于菲涅耳带原理的超面元技术的研究,这些技术的有效应用,对保护深层有效波的低频信号、消除深层构造假象、提高道集的覆盖次数和提高信噪比具有重要的理论和实际意义.在提高地震资料信噪比的基础上,进行了Kirchhoff积分叠前深度偏移研究,结果表明在速度变化较为剧烈的地区,叠前深度偏移的成像精度要高于叠前时间偏移.速度模型是深度域成像的关键,在初始速度模型建立上,研究并应用了二维速度模型约束下的三维速度分析技术,在此基础上,依据测井资料和区域地质研究的成果进行速度模型的优化分析,给出叠前深度偏移的速度体.上述提高信噪比和成像精度的方法在古龙地区深层断陷期地层取得了良好的应用效果,为古龙断陷结构的地质认识奠定了坚实基础.更多还原

【Abstract】 The geological condition is complex and the seismic data is poor in Gulong depression in north of Songliao basin,therefore improving seismic data S/N ratio and seismic imaging are the research focus for hydrocarbon exploration.The seismic data imaging algorithm is given in this paper for improving the imaging precision,the approach to improve S/N ratio includes cross-spread surface wave suppress,subtract method for internal multiples and supper surface stack technique.The above approaches are useful for improving S/N ratio,protecting the low frequency reflection primary,removing structure error and improving the fold number in CMP gather.The prestack depth migration (PSDM) imaging is finished via application of Kirchhoff integration solution of wave equation,comparison with the PSTM,PSDM is applied effectively for media in which velocity variation along the radial and vertical direction is strong,i.e.PSDM is a better migration algorithm for imaging complex geological structure.The high precision velocity model is necessary in PSDM,the initial velocity model is constrained by two-dimensional long offset seismic data,during the course of velocity iteration and optimizing,the well logs and geological knowledge is introduced,and the final velocity body is proposed for PSDM.All imaging techniques are applied in seismic data imaging in Gulong downfaulted basin,the better imaging result was acquired and the proposed technologies are useful for determination of geological structure in Gulong fault depression area.更多还原